Omega-3s

June 1st, 2013

The American Heart Association recommends eating at least two servings of fish per week. Fish, particularly cold-water, fatty fish such as salmon, mackerel, herring, sardines, trout and tuna, contain omega-3 fatty acids that help to protect against heart disease.

Omega-3s can help prevent blood platelets from clotting and sticking to artery walls in the form of cholesterol-rich plaques. Most heart attacks happen when blood clots lodge in veins and arteries, preventing blood from circulating properly. Omega-3s may also help prevent inflammation in diseases such as rheumatoid arthritis, and lack of omega-3s may also cause mood disorders such as post-partum depression.

All seafood contains some, including non-fatty fish, such as halibut, flounder, perch, trout and cod. Shrimp, lobster, clams, and oysters also provide decent amounts of omega-3s, as do freshwater fish.

Wild fish are not richer in omega-3 fish oils than farm-raised varieties. Farm-raised fish such as salmon and trout won't grow without omega-3 fatty acids in their diet, so fish farmers add it to the fish meal. Farmed catfish and tilapia, however, do not need omega-3 fatty acids, so these farm-raised fish have little or no omega-3s. In the wild, fish get their omega-3s from algae, plankton and other fish that they may eat.

You don't need to eat fish to get omega-3s. You can get omega-3s by eating whole grains, beans, such as soybeans and seeds. Flaxseeds are among the richest plant sources of omega-3s.

Many people avoid fish because of fear of mercury poisoning. Nearly all fish contain some amount of methyl mercury, which theoretically can damage nerves, particularly during fetal growth. Mercury is released into the air by pollution. Rainwater brings it into streams and oceans, where bacteria transform it into methyl mercury. Fish get their dose as they feed on algae and other organisms. Older, larger fish that eat other fish accumulate the most methyl mercury, so big carnivores such as swordfish and tuna pose the greatest risk to susceptible populations. Methyl mercury is stored in the flesh and there is no way to remove it.

The Food and Drug Administration recommends that pregnant women and women who might become pregnant, nursing mothers, and young children not eat shark, swordfish or large tunafish. They should eat plenty of other types of fish and shellfish. If a pregnant woman chooses to avoid seafood, she should make sure she gets plenty of omega-3's from seeds such as flaxseed, or from supplements. The FDA does not recommend any limits on fish consumption for the general population.